Mechanisms to understand the basis of species invasiveness

生物入侵是全球生物多样性变化的主要来源。了解在建立-传播阶段和影响阶段促成入侵成功的因素，对于减少与引入非土著物种(NIS)相关的生态、经济和健康问题至关重要。先前的工作已经确定，一些引入并建立在新生态系统中的NIS将比在相同营养水平上互补的本地物种产生更大的生态影响，这可能是由于猎物的天真。尽管最近的工作集中在功能反应的差异上-动物的喂食率相对于食物密度，但事实证明，开发通用的方法来预测NIS的影响是非常具有挑战性的。这项工作揭示了入侵(即高影响)NIS通常比其本土类似物更高的摄食率。然而，这些摄食率差异的根本基础还没有得到解决，也没有不同分类组之间模式的一般性。*在这项提议中，我将对来自广泛环境--包括陆地和水环境--以及营养水平--捕食者与食草动物--的NIS和本地物种进行比较摄食试验，以测试功能反应的差异。所选的分类群将包括广泛不同的分类群，包括甲虫、贻贝、鱼、海鞘和螃蟹，使我们能够检查摄食率差异的一般性。对甲虫的喂养试验将被录像，这将使我们能够确定该物种的行为模式(例如，时间预算、攻击率)。功能反应是通过生物体的生理与环境的相互作用来表达的。当基因被激活时，会产生mRNAs，而这些基因的上调或下调会产生或多或少的这些分子。将这些分子翻译成蛋白质会产生反应(即。摄食率)。我们将使用候选基因方法应用转录组学，即假设在捕食/草食效率中发挥作用的特定基因将成为靶点。如果侵袭性有分子基础，我们预计基础消化酶(如α-淀粉酶)、代谢基因(如。在侵袭性NIS和本地物种中，感觉基因(例如视蛋白基因)或肌肉基因(例如原肌球蛋白)的表达应该是不同的。我们的研究还将探索环境温度和生命阶段对这些结果的重要性。*

Biological invasions are a leading source of biodiversity change globally. Understanding the factors that contribute to invasion success at both the establishment-spread stage and impact stage are vital to reducing ecological, economic and health problems associated with introduction of nonindigenous species (NIS). Prior work has determined that some NIS that are introduced to and establish in a new ecosystem will have a greater ecological impact than do complementary native species at the same trophic level, possibly owing to prey naivety. It has proven very challenging to develop generalities to predict NIS impact, though recent work has focused on differences in functional responses - the feeding rate of an animal relative to food density. This work revealed generally higher feeding rates by invasive (i.e. high impact) NIS than their native analogues. However, the underlying basis for these feeding rate differences has not been addressed, nor has the generality of the pattern across different taxonomic groups.***In this proposal I will conduct comparative feeding trials of NIS and native species from a broad array of environments - including terrestrial and aquatic environments - and trophic levels - predators versus herbivores - to test for differences in functional responses. Taxa selected will include broadly different taxonomic groups including beetles, mussels, fishes, ascidians and crabs, allowing us to examine the generality of feeding rate differences. Feeding trials of beetles will be videotaped, which will allow us to determine the species' behavioural repertoires (e.g. time budgets, attack rate). Functional responses are expressed through the interaction of an organism's physiology with its environment. When active, genes produce mRNAs, and up-regulation or down-regulation of these genes produces more or fewer of these molecules. Translation of these molecules into proteins enacts the responses (ie. feeding rate). We will apply transcriptomics using a candidate gene approach, whereby specific genes hypothesized to play a role in the efficiency of predation/herbivory, will be targeted. If invasiveness has a molecular basis, we expect that basic digestive enzymes (e.g. α-amylases), metabolic genes (eg. ATPases), sensory genes (e.g. opsin genes), or muscle genes (e.g. tropomyosin) should be differentially expressed in invasive NIS versus native species. Our studies will also explore the importance of ambient temperature and life stages to these results. *** *** *** **